See below

Blend 1 cup sugar & 1/2 cup water in small saucepan. Boil until first
indication of thread appears (230 on candy thermometer). Remove from
heat. Stir in 1/4 cup confectioners sugar. If icing becomes sugary
while brushing cookies, reheat slightly, adding a little water until
clear again. Any leftover icing may be used on fruitcake or other
fruit bars.